Implant Device Particularly Useful For Implantation In the Intravascular System For Diverting Emboli

ABSTRACT

A device for implantation in the body of a subject to divert solid particles from entering branch passageways, particularly useful for diverting emboli from branch blood vessels. The implant device includes an anchoring section for firmly anchoring in the branch blood vessel, and a diverter section projecting into the main blood vessel at the upstream side of the branch blood vessel. The diverter section is constructed to permit blood flow through the main blood vessel but includes an outer surface facing the upstream side of the main blood vessel effective to divert emboli in the blood from entering the branch blood vessel.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to implant devices for implantation in thebody of a subject to divert solid particles in a body fluid flowingthrough a main passageway of the subject, from entering a branchpassageway downstream of the main passageway. The invention isparticularly useful as an implant device for implantation in thevascular system for diverting emboli, and is therefore described belowwith respect to such application, but it will be appreciated that theinvention could advantageously be used in other applications, such asdiverting solid particles in other body fluids, e.g., urine, bile, etc.,from entering small passageways in the body.

An ischemic stroke is caused by sudden occlusion of an artery supplyingblood to the brain. Such an occlusion may be caused by emboli in theblood flow through the aorta. Many devices have been developed to reducethe possibility of emboli entering the carotid arteries in order toreduce the incidence of ischemic strokes. Examples of suchpreviously-developed devices are described in U.S. Pat. Nos. 6,258,120,6,348,063, and International Patent Application PCT/IL02/00984 publishedas International Publication No. WO03/047648 A3 on Jun. 12, 2003.

Generally speaking, the known devices are anchored within the aorta suchas to overlie the juncture with the carotid arteries. The known devicesare generally of a mesh-like construction, e.g. an open braidconstruction, having openings sufficiently large to pass the bloodtherethrough, but to intercept emboli and to divert them from thecarotid arteries.

Many of the known devices, however, have inherent drawbacks. One suchdrawback is that the actual trapping of an embolus may result inblockage of blood flow to the carotid arteries. Another inherentdrawback in some of the known devices is that the anchoring of thedevice is insufficient such that the device may be dislodged by theblood flow. A further possible disadvantage in some of the known devicesis that they may to create an unduly high degree of turbulence in theblood flow through the aorta.

OBJECT AND BRIEF SUMMARY OF THE PRESENT INVENTION

An object of the present invention is to provide an implantable devicehaving advantages in one or more the above respects, and thereforeparticularly useful for diverting solid particles in general, and emboliin particular, from branch blood vessels or other fluid passageways inthe body.

According to one aspect of the present invention, there is provided animplant device for implantation in the body of a subject to divert solidparticles in body fluid flowing through a main passageway of thesubject, from entering a branch passageway downstream of the mainpassageway, the implant device comprising: an anchoring section of anexpansible tubular construction for firmly anchoring the implant devicein the branch passageway; and a diverter section integrally formed withthe anchoring section to project into the main passageway at theupstream side of the branch passageway when the anchoring section isanchored in the branch passageway; the diverter section being anextension protruding from the branch passageway into the mainpassageway. It is constructed to permit flow of the body fluid throughthe main passageway, but including an outer surface facing the upstreamside of the main passageway effective to divert solid particles in thebody fluid from entering the branch passageway.

As indicated earlier, the invention is particularly useful as an implantdevice for diverting emboli from branch blood vessels, such as thecarotid arteries.

Therefore, according to a more particular aspect of the presentinvention, there is provided an implant device for implantation in thecardiovascular system of a subject to divert emboli in blood flowingthrough a main blood vessel of the subject, from entering a branch bloodvessel downstream of the main blood vessel, the implant devicecomprising: an anchoring section of an expansible tubular constructionfor firmly anchoring the implant device in the branch blood vessel; anda diverter section integrally formed with the anchoring section toproject into the main blood vessel at the upstream side of the branchblood vessel when the anchoring section is anchored in the branch bloodvessel; the diverter section being constructed to permit flow of theblood through the main blood vessel, and including an outer surfacefacing the upstream side of the main blood vessel effective to divertemboli in the blood from entering the branch blood vessel.

Several embodiments of the invention are described below for purposes ofexample.

In some described preferred embodiments, the diverter section is formedwith many openings therethrough so as to reduce turbulence of the blood(or other body fluid) flowing through the main blood vessel (i.e., theaorta or other main passageway). In these embodiments, the outer surfaceof the diverter section facing the blood flow is of a convexconfiguration in the direction facing the blood flow, and is ofdecreasing width in the direction towards the center of the artery.

Some embodiments are described when the diverter section is in the formof a curved sheet perforated with a plurality of openings therethrough.Such a structure may be fabricated from a single piece of material byway of laser cutting or etching, thereby avoiding joining techniqueswhich may compromise the material properties.

Other embodiments are described wherein the anchoring section and alsothe diverter section are formed of an open braided material. In one suchdescribed embodiment, the diverter section is of a bulbous configurationintegrally formed with the anchoring section.

A still further embodiment described is particularly useful in divertingemboli from a branch vessel of the artery, wherein the device includes asecond anchoring section of an expansible tubular construction forfirmly anchoring the device in the artery downstream of the branchvessel, and the diverter section is secured between the first and secondanchoring sections.

In the preferred embodiments of the invention described below, thedevice is constructed and dimensioned for implantation in the aorta insuch manner that the anchoring section is to be positioned in thecarotid artery and the diverter section is to project into the aorticlumen.

Such intravascular devices may be implanted according to knownintravascular techniques, for example by using a catheter for deliveringthe device to the treatment site, and having a balloon for expanding thedevice at the implantation site. The anchoring tubular structure in thebranch vessel can be made of self-expanding alloy such as Nitinol, orother memory alloy. Since the anchoring is effected in the branchvessel, e.g. a carotid artery, rather than in the aorta experiencingstrong blood flow, there is less chance that the device will bedislodged by blood flow. Moreover, since in most embodiments thediverter section of the device projects a relatively small distance intothe aorta, there is less chance of interfering with the blood flowthrough the aorta or creating undue turbulence in the blood flow throughthe aorta. Moreover, the diverter portion is gently curved distally inthe aorta to reduce turbulence. In addition, since an outer surface ofthe diverter faces the upstream side of the main passageway (aorta), andis therefore effective to divert the emboli from entering a branchvessel, there is less likelihood of clogging the diverter by a particlelodged in the diverter.

Further features and advantages of the invention will be apparent fromthe description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, withreference to the accompanying drawings, wherein:

FIG. 1 illustrates one form of implantable intravascular deviceconstructed in accordance with the present invention;

FIG. 2 illustrates the device of FIG. 1 implanted in the carotid orbrachiocephalic artery protruding into the aortic lumen;

FIG. 3 illustrates a modification in the construction of the device ofFIG. 1;

FIG. 4 illustrates the device of FIG. 3 implanted in as in FIG. 2;

FIG. 5 illustrates another implantable intravascular device constructedin accordance with the present invention;

FIG. 6 illustrates the device of FIG. 5 implanted as in FIG. 2;

FIG. 7 a is a section view along lines VII-VII of FIG. 5;

FIG. 7 b is an enlarged fragmentary view illustrating the constructionof the device of FIG. 5;

FIG. 8 illustrates a further implantable intravascular deviceconstructed in accordance with the present invention;

FIG. 9 illustrates the device of FIG. 8 implanted as in FIG. 2;

FIG. 10 illustrates a modification in the construction of theimplantable intravascular device of FIG. 8;

FIG. 11 illustrates a still further implantable intravascular deviceconstructed in accordance with the present invention for implantation asin FIG. 2;

FIG. 12 illustrates the device of FIG. 11 from a view of 90° withrespect to the view of FIG. 11; and

FIG. 13 more particularly illustrates the device of FIGS. 11 and 12.

It is to be understood that the foregoing drawings, and the descriptionbelow, are provided primarily for purposes of facilitating understandingthe conceptual aspects of the invention and possible embodimentsthereof, including what is presently considered to be a preferredembodiment. In the interest of clarity and brevity, no attempt is madeto provide more details than necessary to enable one skilled in the art,using routine skill and design, to understand and practice the describedinvention. It is to be further understood that the embodiments describedare for purposes of example only, and that the invention is capable ofbeing embodied in other forms and applications than described herein.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 illustrates one form of expansible intravascular device forimplantation in an artery, particularly in a branch vessel of the aortaas shown at 2 in FIG. 2, in order to divert emboli in the blood flowthrough the aorta from passing into certain branch vessels, namely theright brachiocephalic trunk 4, the common carotid artery 6, and the leftsubclavian artery 8.

As shown particularly in FIG. 1, the implantable device, thereingenerally designated 10, includes an anchoring section 11 and a divertersection 12 integrally formed with the anchoring section. Anchoringsection 11 is of an expansible tubular construction for firmly anchoringthe device in the branch vessel 4 when the device is in its expandedcondition, such that when the anchoring section is anchored in thebranch vessel, the diverter section 12 is located at the upstream sideof the branch vessel 4 and projects into the aorta lumen 2, and theouter surface of the diverter section faces the upstream side of theaortic lumen.

As more particularly shown in FIG. 1, anchoring section 11 includes aproximal end 13 to be located proximal to the aorta 2 when the anchoringsection is anchored in blood vessel 4, a distal end 14 to be locateddistal from the aorta, and a passageway (indicated by broken lines 15)from the proximal end 13 through the distal end 14. The diverter section12 is integrally formed with the proximal end 13 of the anchor section11. When the device is deployed as illustrated in FIG. 2, it is locatedat the upstream side of blood vessel 4 and projects into the aorta lumen2. In addition, and as indicated above, the outer surface of divertersection 12 (rather than the inner surface as in the previously-citedpatents) faces the upstream side of the aorta. Such an arrangement thuspermits blood flow through the aorta 2 into the branch vessel 4, butdiverts emboli in the blood flow from entering branch vessel 4, and alsoto some extent branch vessels 6 and 8. In addition, there is a reduceddanger of clogging the diverter, and also a reduced danger ofdislodgement of the implant device.

In the embodiment illustrated in FIGS. 1 and 2, both anchor section 11and diverter section 12 of the implantable device 10 are shown as of asheet-like construction. For example, anchor section 11 could be in theform of a coiled sheet which, during delivery to the implantation site,is tightly coiled so as to have a reduced diameter; at the employmentsite, it is expanded by the opening of the coil to become firmlyanchored in the branch vessel 4. Anchor section 11, could also be of anetlike mesh construction, such as produced by laser cutting or etchingaccording to known techniques for producing stents. As a furtherpossibility, anchor section 11 could also be of an open braidconstruction, as described below with respect to other embodiments,which is expanded by a balloon to firmly grip the inner surfaces of thebranch vessel 4 in order to firmly anchor it therein.

In the embodiment of FIGS. 1 and 2, diverter section 12, integrallyformed at end 13 of the anchor section 11, is shown as being of aperforated sheet-like construction formed with a plurality of openings16 therethrough so as to reduce turbulence of the blood flow through theartery. As also seen in FIG. 1, the outer surface of anchor section 12facing the blood flow, i.e., the upstream side of the aorta, is of aconvex configuration so as also to reduce turbulence in the bloodflowing through the aorta 2. The free end 17 of diverter section is of acurved configuration, decreasing in width in the direction towards thecenter of the aorta lumen, also for purposes of reducing turbulence inthe blood flow through the aorta.

FIG. 3 is illustrates an implantable device, therein generallydesignated 20, of very similar construction as device 10 of FIG. 1. Itincludes an anchoring section 21 and a diverter section 22 correspondingto sections 11 and 12 in FIG. 1. In this case, however, diverter section22 includes a tubular portion 23 at the end thereof integrally formedwith anchor section 21 and of the same diameter as that section.Diverter section 22 in FIG. 3 is also of a curved convex configurationas diverter section 12 in FIG. 1, and is also formed with a plurality ofopenings 26 corresponding to openings 16 in FIG. 1. In FIG. 3, however,the width of diverter section 22 decreases more sharply towards its freeend, as shown at 26, such as to further reduce turbulence into the bloodflow through the aorta.

FIG. 4 illustrates the device 20 of FIG. 3 implanted in the in the samemanner as described above with respect to FIG. 2.

FIG. 5 illustrates another implantable intravascular device, thereingenerally designated 30, but constructed of an open braid material.Thus, as shown in FIG. 5, implantable device also includes an anchoringsection 31 and a diverter section 32 integrally formed with theanchoring section.

The anchoring section 31 is of an expansible tubular construction, asdescribed above with respect to FIGS. 1-4, for firmly anchoring thedevice in the branch vessel 4 (FIG. 6) when the device is in itsexpanded condition.

The diverter section 31 also includes a projecting surface located atthe upstream side of branch vessel 4, when the device is anchoredtherein, and projecting into the lumen of the aorta 2. In this case,however, anchoring section 32 is of a bulbous or mushroom configurationsuch that it projects into the aorta 2 completely around the mouth ofthe branch vessel 4. Thus, as shown particularly in FIG. 5, the outersurface of one side 32 a (the left-facing side) of the bulbous divertersection 32 faces the upstream side of the lumen, and is thereforeprimarily effective to divert emboli from entering the branch vessel,while the bulbous shape of this section decreases the turbulence of theblood flowing through the aorta. As shown particularly in FIG. 7 a, theopposite side 32 b of the bulbous diverter section 32 is formed with anopening 32 c which leads into the interior of the diverter section 32.Opening 32 c allows the introduction of a catheter, if desired, into thebranch vessel in which the diverter is anchored.

Implant device 30, illustrated in FIGS. 5-7 b thus also permits theblood flow to the branch vessel 4, as well as through the aorta 2 andthe other branch vessels 6, 8, but diverts emboli in the blood flow fromentering branch vessel 4, and to some extent also branch vessels 6 and8.

Preferably, diverter section 32, and also anchor section 3, are formedof metal or plastic wires, strands or the like, of at least twodifferent diameters. Thus, as shown in FIGS. 5 and 7 b, diverter section32 includes wires of relatively large diameter 33 a to serve as astructural frame for maintaining its bulbous shape, and a plurality orsmall-diameter wires 33 b for defining the net-like mesh construction ofthat section, which permits blood flow therethrough to the branch vessel4, but diverts emboli therefrom. Since anchor section 31 is preferablyconstructed from the same material as diverter section 32, it may alsoinclude large-diameter wires and small-diameter wires, even though sucha netlike mesh construction is not needed for anchoring section 31.

FIGS. 8 and 9 illustrate an implantable device 40 wherein both theanchoring section and diverter section are also formed of an openbraided material. In this case, however, both sections are formed of anopen braid cylinder such that one end 41 of the cylinder constitutes theanchoring section, and the opposite end 42 constitutes the divertersection. As shown in FIGS. 8 and 9, the diverter section 42 ispreferably angled away from the anchoring section 41 in the direction ofthe blood flow through the aorta 2. The latter angle is preferablyabout, or slightly larger than, 270° from the axis of the anchoringsection.

FIG. 10 illustrates an implantable device, therein generally designated50, of similar construction as device 40 in FIG. 7, namely in the formof an open braid cylinder in which one end 51 constitutes the anchoringsection and the opposite end 52 constitutes the diverter section. Inthis case, however, the braided cylinder is formed of strands or wiresof at least two different diameters, namely larger-diameter strands 51a, 52 a, imparting most of the structural strength to the device, andsmaller-diameter wires 51 b, 52 b producing the netlike meshconstruction.

FIGS. 11-12 illustrate another construction of implantable intravasculardevice considerably different from the previously-describedconstructions. Thus, the device illustrated in FIGS. 11-13, thereingenerally designated 60, includes two expansible anchoring sections 61a, 61 b, and a diverter section 62 connected between the two anchoringsections. The two anchoring sections 61 a, 61 b are of differentdiameters such that anchoring section 61 a, upon expansion, is anchoredwithin branch vessel 4, and anchoring section 61 b, upon expansion, isanchored within aorta 2 downstream of branch vessel 4. Diverter section62 is of a planar configuration having large openings. For example, theratio of the open area defined by these openings to the entire areadefined by the outer dimensions of this section (sometimes called the“aspect ratio”) is preferably from 60% to 90%, preferably about 80%.

As shown particularly in FIG. 12, diverter section 62 is of smoothlyincreasing width from anchoring section 61 a to anchoring section 61 b.The short-width end is joined to anchoring section 61 a at the upstreamend of branch vessel 4, and the opposite, large-width end is joined toanchoring section 61 b such that it substantially spans the length, butnot the width, of aorta 2 from a region just at the upstream side ofbranch vessel 4 to a region just past the downstream side of branchvessel 8. As shown particularly in FIG. 12, the width of divertersection 62 is less than the diameter of the aorta, thereby defining flowpassages at its opposite sides, which flow passages, together with thepassages through its openings, result in relative low resistance to theblood flow through the aorta.

Implantable device 60 illustrated in FIGS. 11-13 is preferably alsoformed of an open braided structure of wires or strands of a singlediameter, or of two diameters as described above with respect to FIGS.5-10.

As indicated above, the foregoing constructions of implantableintravascular devices may be delivered to the implantation site anddeployed at the implantation site via catheters according to knowntechniques. Each device is designed to fit a catheter of reasonable sizefor the application, and to have smooth outer surfaces in order to slidefreely within the catheter through potentially tortuous paths. At theimplantation site, the device is deployed from the end of the catheterby suitable means, e.g. by the inflation of a balloon, or removal of aconstraining sheath, to firmly anchor its anchoring section with therespective branch vessel, and to cause its diverter section to projectinto the lumen of the aorta, as described above.

While the invention has been described with respect to several preferredembodiments, it will be appreciated that these are set forth merely forillustrative purposes. For example, the invention could be implementedin implant devices for diverting solid particles in other types of bodyfluid, for example urine, bile, etc. Also, the implant device may becoated, medicated, or otherwise treated as known in conventional stents.Further, the diverter device could be used as a platform for mounting asensor for measuring temperature, composition, or other condition of theblood.

Many other variations, modifications and applications of the inventionwill be apparent.

1. An implant device for implantation in the body of a subject to divertsolid particles in body fluid flowing through a main passageway of thesubject, from entering a branch passageway downstream of the mainpassageway, said implant device comprising: an anchoring section of anexpansible tubular construction for firmly anchoring the implant devicein said branch passageway; and a diverter section integrally formed withsaid anchoring section to project into said main passageway at theupstream side of said branch passageway when the anchoring section isanchored in the branch passageway; said diverter section beingconstructed to permit flow of the body fluid through said mainpassageway, but including an outer surface facing the upstream side ofthe main passageway effective to divert solid particles in the bodyfluid from entering said branch passageway.
 2. The device according toclaim 1, wherein said diverter section is formed with many openingstherethrough so as to reduce turbulence of the fluid flow through saidmain passageway.
 3. The device according to claim 1, wherein said outersurface of the diverter section is of a convex configuration so as toreduce turbulence of the blood flow through said main passageway.
 4. Thedevice according to claim 1, wherein said diverter section is ofdecreasing width in the direction towards the center of said mainpassageway.
 5. The device according to claim 1, wherein said divertersection is in the form of a curved planar sheet perforated with aplurality of openings therethrough.
 6. The device according to claim 1,wherein said anchoring section and said diverter section are formed ofan open braided material.
 7. The device according to claim 6, whereinsaid diverter section is of bulbous configuration integrally formed withsaid anchoring section, and includes an opening at the downstream sidecommunicating with the interior of the anchoring section.
 8. The deviceaccording to claim 6, wherein both said anchoring section and saiddiverter section are formed of an open braid cylinder such that one endof the open braid cylinder constitutes said anchoring section foranchoring in the branch passageway, and the opposite end of said openbraid cylinder constitutes said diverter section for projecting intosaid main passageway.
 9. The device according to claim 8, wherein saiddiverter section of the open braid cylinder is angled away from theanchoring section of the open braid cylinder in the downstream directionof fluid flow.
 10. The device according to claim 6, wherein said openbraid material is formed of strands of at least two different diameters.11. The device according to claim 1, wherein the device includes asecond anchoring section of an expansible tubular construction forfirmly anchoring the device in said main passageway downstream of saidbranch passageway, said diverter section being secured between saidfirst and second anchoring sections.
 12. The device according to claim11, wherein said diverter section is of a planar configuration and of awidth smaller than the diameter of said main passageway.
 13. The deviceaccording to claim 1, wherein the device is constructed and dimensionedfor implantation in the aorta artery such that the anchoring section isto be anchored in the carotid artery and the diverter section is toproject into the aorta lumen.
 14. An implant device for implantation inthe cardiovascular system of a subject to divert emboli in blood flowingthrough a main blood vessel of the subject, from entering a branch bloodvessel downstream of the main blood vessel, said implant devicecomprising: an anchoring section of an expansible tubular constructionfor firmly anchoring the implant device in said branch blood vessel; anda diverter section integrally formed with said anchoring section toproject into said main blood vessel at the upstream side of said branchblood vessel when the anchoring section is anchored in the branch bloodvessel; said diverter section being constructed to permit flow of theblood through said main blood vessel, and including an outer surfacefacing the upstream side of the main blood vessel effective to divertemboli in the blood from entering said branch blood vessel.
 15. Thedevice according to claim 14, wherein said diverter section is formedwith many openings therethrough so as to reduce turbulence of the bloodflow through said main blood vessel.
 16. The device according to claim14, wherein said outer surface of the diverter section is of a convexconfiguration so as to reduce turbulence of the blood flow through saidmain blood vessel.
 17. The device according to claim 14, wherein saiddiverter section is of decreasing width in the direction towards thecenter of said main blood vessel.
 18. The device according to claim 14,wherein said diverter section is in the form of a curved planar sheetperforated with a plurality of openings therethrough.
 19. The deviceaccording to claim 18, wherein said anchoring section and said divertersection are formed of an open braided material.
 20. The device accordingto claim 18, wherein said diverter section is of bulbous configurationintegrally formed with said anchoring section, and includes an openingtherethrough communicating with the interior of the anchoring section.21. The device according to claim 20, wherein both said anchoringsection and said diverter section are formed of an open braid cylindersuch that one end of the open braid cylinder constitutes said anchoringsection for anchoring in the branch blood vessel, and the opposite endof said open braid cylinder constitutes said diverter section forprojecting into said main blood vessel.
 22. The device according toclaim 18, wherein said diverter section of the open braid cylinder isangled away from the anchoring section of the open braid cylinder in thedownstream direction of blood flow.
 23. The device according to claim14, wherein said open braid material is formed of strands of at leasttwo different diameters.
 24. The device according to claim 14, whereinthe device includes a second anchoring section of an expansible tubularconstruction for firmly anchoring the device in said main blood vesseldownstream of said branch blood vessel, said diverter section beingsecured between said first and second anchoring sections.
 25. The deviceaccording to claim 24, wherein said diverter section is of a planarconfiguration and of a width smaller than the diameter of said mainblood vessel.
 26. The device according to claim 14, wherein the deviceis constructed and dimensioned for implantation in the aorta artery suchthat the anchoring section is to be anchored in the carotid artery andthe diverter section is to project into the aorta lumen.